Saini S, Stark D D, Hahn P F, Wittenberg J, Brady T J, Ferrucci J T
Radiology. 1987 Jan;162(1 Pt 1):211-6. doi: 10.1148/radiology.162.1.3786765.
The potential of superparamagnetic ferrite particles as a contrast agent for magnetic resonance (MR) imaging was studied by in vitro MR spectroscopy and in vivo MR imaging in laboratory animals. After aqueous preparations of ferrite particles were administered intravenously, MR spectroscopy showed greatly decreased T2 relaxation times of liver and spleen, with only minimally altered T1, and no changes in lung, kidney, or muscle. Effects occurred within 30 minutes of injection and persisted for more than 6 months. MR imaging with pulse sequences that provide T2-dependent contrast demonstrated that ferrite produced profound signal loss from liver, spleen, and bone marrow. Sequestration of ferrite particles in hepatic reticuloendothelial cells was confirmed by means of light and electron microscopy. Because ferrite has a potent effect on MR signal and exhibits tissue-specific localization, it warrants further study as a contrast agent for MR imaging of the reticuloendothelial system (i.e., liver, spleen, and bone marrow).
通过体外磁共振波谱和对实验动物进行体内磁共振成像，研究了超顺磁性铁氧体颗粒作为磁共振（MR）成像造影剂的潜力。静脉注射铁氧体颗粒的水性制剂后，磁共振波谱显示肝脏和脾脏的T2弛豫时间大幅缩短，T1仅有微小改变，而肺、肾或肌肉无变化。注射后30分钟内出现效应，并持续超过6个月。使用提供T2依赖对比度的脉冲序列进行磁共振成像表明，铁氧体使肝脏、脾脏和骨髓产生明显的信号损失。通过光学和电子显微镜证实铁氧体颗粒被肝网状内皮细胞摄取。由于铁氧体对磁共振信号有显著影响并表现出组织特异性定位，因此有必要进一步研究其作为网状内皮系统（即肝脏、脾脏和骨髓）磁共振成像造影剂的潜力。
